E.N.S.O. Discussion

[northwestsnow]

Don't want a Nina on steroids!!

[Summer Sun]

 

[summer blizzard]

07OCT2020 1.2: -1.2, 3.4: -1.2  

14OCT2020 1.2: -1.2, 3.4:-1.4 

21OCT2020 1.2: -1.1, 3.4: -1.4

[Mapantz]

I'm surprised at the lack of comments regarding the news of moderate to strong la nina?!

[Catacol]

8 minutes ago, Mapantz said:

I'm surprised at the lack of comments regarding the news of moderate to strong la nina?!

I should have posted this ripped chart here instead of the winter thread.

Only 2 cold months in strong Niña years since 1950: Feb 1956 at -0.2 CET and Dec 2010 at -0.7 CET. But it still looks unclear to me whether we will get a sustained period of Niña circulation at strong levels or just a pass through it. JAS came in at -0.6 on the ENSO index and from the look of it ASO will come in at about -0.8. This puts us quite a long way behind 2010/11 values which were already at -1.4. I’m very keen to see the UKMO update on 12 Nov (or thereabouts) to see whether things may bottom out in OND and not drop below -1.5.

The closest Niña analog in terms of depth/shape looks to me to be 1955 and as already stated Feb 56 was cold. Mind you....back then our climate/weather was a very different beast...

 

 

[Bullseye]

2 hours ago, Catacol said:

I should have posted this ripped chart here instead of the winter thread.

Only 2 cold months in strong Niña years since 1950: Feb 1956 at -0.2 CET and Dec 2010 at -0.7 CET. But it still looks unclear to me whether we will get a sustained period of Niña circulation at strong levels or just a pass through it. JAS came in at -0.6 on the ENSO index and from the look of it ASO will come in at about -0.8. This puts us quite a long way behind 2010/11 values which were already at -1.4. I’m very keen to see the UKMO update on 12 Nov (or thereabouts) to see whether things may bottom out in OND and not drop below -1.5.

The closest Niña analog in terms of depth/shape looks to me to be 1955 and as already stated Feb 56 was cold. Mind you....back then our climate/weather was a very different beast...

 

 

Quite liking the analog of 1955. Another two points to add based on 1955 is we dropped into solar minimum around summer/autumn 1954 much like last year likely being solar minimum (Nov/Dec 2019). Another to add would be QBO levels going into 1955/56 winter are of similar values to now - weakly positive, that said the QBO did descend into easterly phase come Feb 1956, unlikely this year. Again though as you mentioned different times despite this with climate changes, maybe best sticking to analog years from early 90s or so onwards - low sample size. 

[SqueakheartLW]

I do remember someone on here not long ago wanting NINO index data which wasn't just NINO 3.4 data which is easy to find

I have discovered some decent NINO data sets that go right back to 1870

The links for each NINO Region are below

The first link is the actual sea surface temperature in C. The second link is the anomaly

NINO 1+2

https://psl.noaa.gov/gcos_wgsp/Timeseries/Data/nino12.long.data

https://psl.noaa.gov/gcos_wgsp/Timeseries/Data/nino12.long.anom.data

NINO 3

https://psl.noaa.gov/gcos_wgsp/Timeseries/Data/nino3.long.data

https://psl.noaa.gov/gcos_wgsp/Timeseries/Data/nino3.long.anom.data

NINO 3.4

https://psl.noaa.gov/gcos_wgsp/Timeseries/Data/nino34.long.data

https://psl.noaa.gov/gcos_wgsp/Timeseries/Data/nino34.long.anom.data

NINO 4

https://psl.noaa.gov/gcos_wgsp/Timeseries/Data/nino4.long.data

https://psl.noaa.gov/gcos_wgsp/Timeseries/Data/nino4.long.anom.data

Feast your eyes upon all that data I just happened to stumble upon when looking for historical NINO indexes

[summer blizzard]

Not sold on 56 as an analogue being second year, our tropics are quite robust.

ONI will be 0.9/1.0 for ASO.

[virtualsphere]

On 30/10/2020 at 15:07, SqueakheartLW said:

I do remember someone on here not long ago wanting NINO index data which wasn't just NINO 3.4 data which is easy to find

I have discovered some decent NINO data sets that go right back to 1870

That was probably me, I was trying to plot the ENSO data against the CET as mentioned in this post but the dataset I used only went back to 1950.  I'll take a look when I get a minute, it will be interesting to use a longer period to see how the results come back, especially given some of the mention of 1917 and 1956.  

I did also look at the different ENSO regions but couldn't really find an effective way to plot this.  Something to file for now and come back to!

Talking of strong Nina events, this report gives some background and mentions briefly 1917 & 1955-56 although the main focus is on the effects of the 2010 Nina in Australia.

[Premiere Neige]

On 03/11/2020 at 22:36, virtualsphere said:

That was probably me, I was trying to plot the ENSO data against the CET as mentioned in this post but the dataset I used only went back to 1950.  I'll take a look when I get a minute, it will be interesting to use a longer period to see how the results come back, especially given some of the mention of 1917 and 1956.  

I did also look at the different ENSO regions but couldn't really find an effective way to plot this.  Something to file for now and come back to!

Talking of strong Nina events, this report gives some background and mentions briefly 1917 & 1955-56 although the main focus is on the effects of the 2010 Nina in Australia.

Hopefully we don't get into strong territory. Temperature has started to tick up in 3.4 region over the past few days....

[virtualsphere]

10 hours ago, Premier Neige said:

Hopefully we don't get into strong territory. Temperature has started to tick up in 3.4 region over the past few days....

Strong Nina might not be so bad for a colder winter when you look further back in the data.  Here are some more visualisations using the historical datasets @SqueakheartLW posted above, and when you go back to 1870 there are quite a few examples of Oct-Dec sub -1 anomaly Ninas with sub 3C CETs for the following winter.   First up, Nino 3.4 Oct - Dec average anomaly plotted against following winter CET with the shape indicating 3.4 anomaly (triangle positive, circle negative): 

And now Nino 1+2 Oct - Dec average anomaly, this time with the shape indicating 1+2 anomaly (again triangle positive, circle negative).  Looks like we really don't want this to be strongly positive for colder winters!

  

[Premiere Neige]

1 hour ago, virtualsphere said:

Strong Nina might not be so bad for a colder winter when you look further back in the data.  Here are some more visualisations using the historical datasets @SqueakheartLW posted above, and when you go back to 1870 there are quite a few examples of Oct-Dec sub -1 anomaly Ninas with sub 3C CETs for the following winter.   First up, Nino 3.4 Oct - Dec average anomaly plotted against following winter CET with the shape indicating 3.4 anomaly (triangle positive, circle negative): 

And now Nino 1+2 Oct - Dec average anomaly, this time with the shape indicating 1+2 anomaly (again triangle positive, circle negative).  Looks like we really don't want this to be strongly positive for colder winters!

  

Isn't sub -1.5 considered strong as opposed to-1? I understood it that central based la nina was better for UK cold when weak to moderate. Who knows!

[Premiere Neige]

Another slight increase in temperature in the 3.4 region....

[Kirkcaldy Weather]

 

[virtualsphere]

20 hours ago, Premier Neige said:

Isn't sub -1.5 considered strong as opposed to-1? I understood it that central based la nina was better for UK cold when weak to moderate. Who knows!

You may well be right re. strong, will leave that to the experts

The coldest Nina winters especially more recently are indeed in the 0 to -1 range - but there are actually very few examples below -1.5 and they are pretty evenly spread across the CET range from 1916/17 at a chilly 1.5C to 1988/89 at 6.5C.  There's only 3 winters which average Oct - Dec periods with negative ENSO anomalies lower than -1.5 in both 3.4 and 1+2 regions, 1916/17, 1955/56 and 2007/08 and these return CETs of 1.5, 2.9 and 5.6, so that's 2 out of 3 that are sub 3C.   There's a lot of other factors at play, no doubt, but looking at these has made me more confident that we can still get cold weather with strong(ish) La Nina than if it was strong El Nino - there are no examples of a winter CET below 3.5C following a positive anomaly greater than 1.5 in either 1+2 or 3.4 regions for the entire dataset (and there are more of them)!

Of course worth mentioning this is averaged over 3 months which is likely to reduce the strength of any individual monthly anomalies.

[summer blizzard]

ONI for ASO came in at -0.9.

ONI for October alone will come in at -1.4.

 

 

[Premiere Neige]

Temperature in the 3.4 region continues to tick up. Now at -1.351....

[SqueakheartLW]

54 minutes ago, Premier Neige said:

Temperature in the 3.4 region continues to tick up. Now at -1.351....

Take that CFS. How wrong you are with your Super Nina prediction

[summer blizzard]

04NOV2020 - 1.2: -1.0, 3.4: -1.5 

1 hour ago, SqueakheartLW said:

Take that CFS. How wrong you are with your Super Nina prediction

We are still likely to see another bout of trade winds develop once tropical convection becomes suppressed so i would imagine that Nina continues to strengthen. 

[mb018538]

38 minutes ago, summer blizzard said:

04NOV2020 - 1.2: -1.0, 3.4: -1.5 

We are still likely to see another bout of trade winds develop once tropical convection becomes suppressed so i would imagine that Nina continues to strengthen. 

Where does a sub -2c Nina sit in the grand scheme of things? I'm not particularly an expert in the area, but interested none the less! 

[summer blizzard]

23 minutes ago, mb018538 said:

Where does a sub -2c Nina sit in the grand scheme of things? I'm not particularly an expert in the area, but interested none the less! 

I'm not sure. I imagine a few events have recorded a weekly value in 3.4 that low but never a tri-monthly. I doubt we'll get a tri-monthly value that low (2010 was better coupled and 2007 more basin wide but we are close). 

[virtualsphere]

6 hours ago, summer blizzard said:

I'm not sure. I imagine a few events have recorded a weekly value in 3.4 that low but never a tri-monthly. I doubt we'll get a tri-monthly value that low (2010 was better coupled and 2007 more basin wide but we are close). 

The only monthly values below -2C in the 3.4 region I can see are Jan 1890, Feb 1890, Nov 1973, Dec 1973, Jan 1974, Oct 1988, Nov 1988.

[Premiere Neige]

Another increase in region 3.4. We are now at -1.225....

[Premiere Neige]

However, 1 + 2 temperature reducing. Not so long ago this was looking like a central based Niña, could this turn into an east based Niña?

[mountain shadow]

2 minutes ago, Premier Neige said:

Another increase in region 3.4. We are now at -1.225....

So, a moderate/low La Nina looks more likely and is my understanding correct, that this gives a better chance of a colder Winter?